"I live in SC but have my epileptic, bipolar, ADHD son on CBD and I personally take CBD for both fibromyalgia and vestibular migranes but we travel frequently to states that do allow MM, it would be convenient while we are there to source new products or experiment with treatments. Is obtaining a card possible without an address in a state that has this available?"
This is a great question. This is highly dependent on the state and the laws in each state. Unfortunately, the laws are so different state by state that there is now way to know unless you look up the government regulations for that state. I would also do a back up check in with a dispensary within that state to make sure you do not go through the trouble and find no one will actually sell product to you.
You may not legally transport MM over state lines, this is illegal in every state.
In California, you can obtain a medical card as an out of state peron if you have the consultation with the doctor within state lines. That said, some dispensaries will still not serve you without a license. The dispensaries do not always follow the state laws, they often follow what they believe to be the state laws.
I hope this helps!